Joseph peaeson gill



UNITED STATES PATENT OFFICE.

JOSEPH PEARSON GILL, OF NEW YORK, N. Y.

SURFACE OF IRON AND STEEL.

SPECIFICATION forming part of Letters Patent No. 284,001, dated August 28, 1883.

' Application filed August 4, 1883. (Specimens) To all whom it may concern;

Be it known that I, J OSEPH PEARSON G-ILL, of New York, in the county of New York and State of New York, have invented a new and are rendered capable of resisting the action of the elements under all circumstancesin which they are liable to be exposed in use, and capable also of withstanding the corrosive action of acids.

Heretofore attempts have been made to effectually protect such articles with a film of oxide of iron. Such a film. besides being an imperfect protection against the action of the elements, is liable to crack and scale under bending or blows of the hammer.

The object of my invention is to produce an article capable both of resisting corrosive action and a destructive agency of bending or of beating, whereby a perfectly-protected article may be produced capable of resisting corrosion under ordinary circumstances.

To this end my invention consists of the surfacing of articles of iron or steel formed of carbon of iron or of carbide and oxide of iron in the metal itself by a change in the quality or nature of the metal, and without the formation of a film or scale 011 the surface thereof.

The process for forming this protective coating or surface in or upon the metal itself and the apparatus useful to carry on the process are described in application filed by me in the United States Patent Office on the 9th day of July, 1883. Briefly, this process consists in placing the articles, properly cleaned from external impurities, in a retort or muffle, and there bringing them to a red heat, preferably applying hydrogen gas; then in applying steam and hydrocarbon vapor, either simultaneously or in succession or alternately. The action of the steam and hydrocarbon vapor, as more fully explained in my application heretofore referred to, effects a change in the metal itself,

rable therefrom as a scale or film, and is capable of resisting corrosive agents and of the action of the hammer or bending.

I am aware that articles of iron have been produced with a steelified surface; also, that articles have been provided with a film of oxide of iron as a protective coating, and I have distinguished my articles from such, and desire to be understood as not claiming so broadly as to include them.

I wish it also to be understood that I apply my protective coating to any articles requiring such protection; but the extent of the protection depends upon the kind of article treated and the purpose for which it is to be used, articles intended to be flexible or bent and exposed only to ordinary atmospheric influences requiring a less degree of surfacing than inflexible articles subject to rough usage and the action of strong corrosive agents.

I claim as my invention The described article of iron or steel, having a practically non-corrodible surface, formed by oxygen and carbon combined with the iron, and produced in substantially the manner set forth, such surface being formed by change in the metal, without film or scale.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOSEPH PEARSON GILL.

Witnesses WM. H. GRENELLE, F. L. MIDDLETON. 

